This blog started as a place to bring objectivity, quantitative analysis, and science to green living, but has evolved to focus more on my research, with some cool science stories mixed in. I reserve the right to write about anything that fascinates me. I'm a senior conservation scientist for The Nature Conservancy, but content posted here is my own. I tweet at @sciencejon and my bio is at https://www.nature.org/science-in-action/our-scientists/jon-fisher.xml

Wednesday, November 1, 2017

I've got a good one for you this month! It's less focused
than usual, but there are three key topics, plus a mix of a few others:

First, if you're
about to delete this unread, please take this survey (which takes <1 minute)
to let me know if you have input on how these summaries could be more
useful: https://www.surveymonkey.com/r/BCVDKQR
. Thanks to all who responded; results are summarized at the end of this email.

Second, the
long-awaited "Natural Climate Solutions" paper from TNC is out. Read
it: it's only 5 pages and will be highly relevant to virtually everyone
working in conservation. It makes a solid case for how immediately investing in
nature to reduce GHGs can buy us much-needed time to bring down emissions and
invent new technology.

Third, a new book
came out Oct 12: Effective Conservation Science: Data Not Dogma. It
includes chapters from myself and several TNC authors, and is full of
fascinating stories of how we react to science that counters conventional
wisdom. I also share related articles below on how we can work through our
biases.

CLIMATE CHANGE /
NATURAL CLIMATE SOLUTIONS

Griscom et al 2017 (the natural climate solutions paper) packs
a lot of good content in, but two things in particular excite me. First is
making the case for massive rapid investment in nature: while we develop new
tech and bring down emissions, we can use proven solutions like trees to buy
time and make progress (see figure 2: nature could get us 37% of mitigation
needs by 2030 at <$100/t CO2e / yr). We need the tech too, but nature is
something that works today to bring down GHGs. Second is breaking down their
top 20 options for nature-based climate mitigation into the theoretical maximum
impact (about 1/2 of which would cost <$100 / t CO2e / yr), what we would
need to hit Paris targets of <2 degrees C, and the subset of mitigation
which is cheap (<$10/t CO2e / yr). See Figure 1 for this breakdown, which highlights
that forests are absolutely critical (2/3 of cost-effective mitigation), and
that the biggest opportunities for cheap mitigation are preventing forest loss
(and improving forest management), improving fertilizer use on farms, and
keeping peatlands intact. The forest goals rely heavily on a small reduction in
grazing lands (4%). I'm leaving out lots of important details to keep this
short: just read the paper. It's worth it. Read all about it (or watch videos)
at https://global.nature.org/initiatives/natural-climate-solutions/natures-make-or-break-potential-for-climate-change

In 1992 E.O. Wilson asserted that invasive species were the
second greatest driver of species extinction (second only to habitat
destruction). He did so without providing evidence or details behind his
calculations, but this claim was rapidly repeated and taken as gospel by
environmental scientists. In fact, TNC played a major role in elevating
Wilson's claim by not only citing it (in a BioScience paper and related book),
but adding that "scientists generally agree" with Wilson's claim
(again without evidence). Chew 2015 tells the captivating story about how this
happened, using clear writing, thought-provoking questions, and numerous
examples of bias in language that should be neutral and scientific. He also
tells us how the idea eventually became subject to critique. I have seen this
phenomenon firsthand; I follow a trail of citation breadcrumbs from authors to
discover a primary source with an assertion that cannot be supported by what's
in the paper (e.g. a book chapter on soil by Rattan Lal). When scientists don't
closely read the papers we cite (or read them at all), our biases blossom and
spread. If you're interested in invasive species or how spurious claims spread,
this is a great read (albeit long).

Warren et al 2017 asks how common it is for scientists to be
biased with regard to invasive species: using value-laden language and favoring
interpretation that emphasizes the impacts of invasive species even when the
data are not clear (as exemplified by the Chew 2015 article). They found bias
to be common, but also that it has been declining since a series of papers in
2004-2005 that argued against language vilifying invasive species. This paper
is fairly simplistic but gets at a key nuance: even a bias which is generally
true is counter-productive in science. This paper shows hope that with awareness
of bias, we can make efforts to at least reduce the expression of that bias in
our work.

Holman et al 2015 provides more evidence of scientific bias,
and argues for the use of "blinding" when conducting research to
limit the potential for bias to affect study results. This means scientists
collecting data don't know whether the subjects or area they're observing is a
treatment or a control. This makes it harder for preconceptions to affect
measurements (whether subjective, or even "rounding" seemingly objective
metrics to fit bias), and they present evidence that nonblind studies often
inflate the effect of the actions being studied. If "working blind"
sounds extreme to you, read my blog post about "Clever Hans" - a
horse who was believed to be able to do math (but in fact was only skilled at
reading when his audience believed he had the right answer):
https://blog.nature.org/science/2015/02/12/horses-doing-math-clever-hans-lessons-conservation-science/

As a final thought on bias, check out the Minasny & McBratney
article in the Soil section below, which challenges a key assertion for TNC's
agriculture work (that boosting soil organic matter improves water holding
capacity). Read the summary below, and observe your feelings and reaction if it
challenges what you believe.

SOIL

Minasny & McBratney 2017 use a meta-analysis to argue
against something generally believed to be true by people working on
sustainable agriculture: they provide evidence that increasing soil organic
matter has a relatively small effect on water holding capacity (particularly
for plant-available water content). If they're right, it reduces TNC's argument
that improving soil health via boosting organic matter on farms will
substantially improve crop resilience to drought. The authors note that soils
that benefit most from increases in organic matter are sandy and very low in
organic matter to begin (both of which make sense). They have a good discussion
of limitations of their analysis, in particular the fact that they focused only
on soil and not what's above it. Cover crops and crop residue / stubble are
likely to add to the small benefits shown via soil. There is also a lot of
nuance and potential to reframe their analysis in a way that could show larger
benefits. At the same time, recognizing that most of us have a bias on this
topic, this is a useful reminder to check our assumptions about both the
efficacy of practices and the key mode of action and metrics that we should
focus on. The authors led a key paper on the "4 per mille" initiative
on boosting soil carbon, so are not hostile to the notion of boosting soil
carbon. You can read a news article about this one here:
https://phys.org/news/2017-10-adding-soil-limited-effect-capacity.html

GENERAL ECOLOGY /
BIODIVERSITY

Remember as a kid how many bugs would get splattered on the
windshield of your car? Ever notice there are less now? A recent study (Hallman
et al 2017) indicates this is a real phenomenon, with dramatic declines in
flying insects. The authors tracked the total biomass of insects at 63
locations within nature preserves in Germany; from 1989 to 2016 biomass
plummeted by 76%. They sampled several habitat types and found consistent
declines. It's alarming to see this within protected areas, although the authors
note virtually all are surrounded by agriculture. That could both pull insects
away from natural areas, and provide more pesticide drift into the natural
areas. Other studies have shown major insect declines, but none this severe,
and I don't know of others within protected areas.

I've been pondering what we think we know and how to
communicate thorny issues (as per data not dogma). I'd recommend a book I'm
reading: "Do I make myself clear?" by Harold Evans, which is helping
me. While not for scientists, I saw my writing sins laid bare in this book. I'm
looking to simplify my writing in science papers, and to better talk about
science in general. I have a long way to go! I'm working on summarizing key
lessons amidst all of the stories in the book. One useful tool is the Hemingway
app, which helps you identify problematic text and how to improve it: http://www.hemingwayapp.com/

AGRICULTURE:

As noted in my August 2017 review, neonicotinoids (neonics
for short) are a class of insecticide currently under close scrutiny for
impacts on bees. Mitchell et al 2017 found neonics in 75% of the 198 honey
samples they tested, although mostly at very low levels. All neonics were at
safe levels for humans, and most were at levels considered safe for bees. This
is useful to show both that these pesticides are very common, that they are
being consumed by bees, and that they often occur in concert with other neonics
(all of which is concerning). But the reporting (and fundraising) around this
has glossed over the very low levels. While 48% of samples had total neonic
levels over a very conservative threshold for potential harm to bees (0.1 ng /
g, a more reasonable (still likely conservative, albeit arbitrary) threshold of
2 ng / g was only detected in 8% of samples. The honey was collected via
"citizen science"; the researchers asked colleagues, friends, and
family to bring them honey produced in a known location. That also raises the
question of whether or not these honey samples are typical.

RESULTS FROM SURVEY
ABOUT THESE SUMMARIES:

I'm guessing the folks who didn't respond would have had
more critical feedback, but overall here's what I learned from the ~40
respondents:

90%
of you usually at least skim these for relevant content

90%
of you found the level of detail about right (including some who said they
could use less detail but were content to tolerate the current length),
the rest found them too long.

Several
folks especially liked both grouping articles by topic, and focusing each
month primarily on one topic. I'll endeavor to keep that up, despite failing
to do so this month.

Some opportunities to improve I'll be mulling over:

Set
up a monthly journal club to talk about the papers (this one is already in
the works, stay tuned for more info and let me know if you would like to
provide input)

Make
a lead theme more clear up front and include a short summary of the entire
email

Tie
each article to TNC's shared conservation agenda

Each
quarter send a list of bullets of main issues under debate in conservation
to encourage us to follow up